Walka Water Works is a heritage-listed 19th-century pumping station at 55 Scobies Lane, Oakhampton Heights, City of Maitland, New South Wales, Australia.

Originally built in 1887 to supply water to Newcastle and the lower Hunter Valley, it has since been restored and preserved and is part of Maitland City Council's Walka Recreation and Wildlife Reserve.

In 1876, George Lloyd, the local representative in the Parliament of New South Wales raised the matter of government help to finance the construction of a water supply for Newcastle.

In 1877 Sir Henry Parkes sent noted British hydraulic engineer William Clark to advise on possible water sources for the Lower Hunter towns.

Clark's report recommended Walka as the site for a water works which would supply 37 000 people at the estimated cost of 170 000 pounds.

By May 1879 the necessary surveys and cost estimates had been sufficiently advanced to allow the ordering of machinery and iron pipes but the government refused to bow to pressure from the Hunter region to sanction full expenditure.

George Blunt built the reservoir, filter beds and settling and clear water tanks and James Watt and Company of Birmingham supplied and erected the three pumping stations installed at Walka in 1886.

[2] Water was pumped from the Hunter River to a reservoir along a brick tunnel approximately 6 feet (1.8 m) in diameter and 9 metres (30 ft) below ground.

[4] The waterworks served as the sole water supply of the Lower Hunter towns from 1887 until 1929 when it was superseded by the Tarro Pumping Station.

[1] Severe droughts in 1902 and 1905-6 produced supply problems and demonstrated that the Hunter River was no longer an adequate water source for the region.

[8] This was eventually resolved, but in December 1953 the power station suffered another setback when one of its oil storage tanks collapsed in gale-force winds.

The internal brickwork is rendered and painted but along its eastern side it retains the profile of the exterior of the main pump house.

[1] A lean to roof and western wall of corrugated iron over a timber frame erected between the workshop and boiler room in 1913.

A steep, centrally located set of concrete steps lead south down an embankment to the filter beds.

[1] The reservoir edges follow the natural land contours on the northern and western sides and are bounded by an earthen embankment made from material excavated during the construction of the tanks, filter beds and pumping station on the southern and eastern ends.

[1] A circular brick structure with an iron trap door is centrally located on the reservoir's north bank and a small valve house is present about 30m from the eastern wall.

Substantial footings and rubble, a tennis court and an approach road flanked by introduced trees remain.

[1] An isolated stand of an endangered ecological community, Lower Hunter Spotted Gum-Ironbark Forest, has survived in the area because the small catchment around the constructed reservoir lake was bordered for historical civic purposes some 150 years ago and has remained relatively secure in tenure and management since.

The bush component acts as an island and a stepping stone for fauna within the (largely cleared) Hunter Valley.

[1] A sparse scatter of plantings from the original period of operation, including an avenue of trees near the Chief Engineer's residence.

[1] The steel steps and concrete footings for the fuel air pump house can be seen at the edge of the rail track below filter bed 7.

[13][1] Walka Water Works was listed on the New South Wales State Heritage Register on 2 April 1999 having satisfied the following criteria.

Establishment of the complex was a major political and engineering achievement, finally providing a permanent supply of clean water to Newcastle residents.

The construction, expansion and demise of the waterworks were vital stages in the establishment and growth of the Hunter Valley Waterboard.

William Clark, a prominent hydraulics engineer and a number of other noteworthy individuals were closely associated with the complexes design, construction and expansion.

[14][1] The place is important in demonstrating aesthetic characteristics and/or a high degree of creative or technical achievement in New South Wales.

The pumphouse, chimney and boiler house are finely executed polychrome brick structures which feature a degree of uniformity in materials, form and scale that is typical of many 19th century public buildings.

The combination of elegant polychrome brick buildings, filter beds, tanks and reservoir with the nearby topography creates an element of considerable cultural interest and beauty within an already attractive landscape.

[17][1] The place has potential to yield information that will contribute to an understanding of the cultural or natural history of New South Wales.

The intact nature of the site makes it an excellent representation of water filtering and reticulation processes of the period.